Apparatus for liquid cooling of pistons in piston-type internal combustion engines



3 1963 cs. J. HELLINGMAN 3, 3,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PlSTONTYPE INTERNALCOMBUSTION ENGINES Filed March 16, 1967 3 Sheets-Sheet 1 I 8 "#w l l 12E 13 5 i a k 17 5 x Inventor.-

GOSEN JOOP HELLINGMAN 42. J ZWMJ AMW ATTO RN EYS 1968 G. J. HELLINGMAN3,413,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PISTON-TYPE INTERNALCGMBUSTION ENGINES 5 Sheets-Sheet 2 Filed March 16, 1967 /n vent or:

GOSEN JOOP HELLINGMAN q, 25.5.5.5 as r BY W 'MJ MMGAW ATTORNEYS Dec. 3,1968 3. J. HELLINGMAN 3,413,963

APPARATUS FOR LIQUID COOLING OF PISTONS IN PISTON-TYPE INTERNALCOMBUSTION ENGINES 5 Sheets-Sheet 3 Filed March 16, 1967 FI'Q'. 4

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GOSEN JOOP HELLINGMAN BY W MQJ ZW ATTQRINEYS United States Patent O3,413,963 APPARATUS FOR LIQUID COOLING OF PISTONS [N PISTON-TYPEINTERNAL COMBUSTION EN- GINES Gosen .loop Hellingman, Zurich,Switzerland, assignor to Sulzer Brothers Limited, Winterthur,Switzerland, a Swiss company Filed Mar. 16, 1967, Ser. No. 623,745Claims priority, application Switzerland, Mar. 18, 1966, 3,996/ 66 8Claims. (Cl. 123-41.36)

ABSTRACT OF THE DISCLOSURE There is disclosed an internal combustionengine having a liquid-cooled piston or pistons. For each piston thereare provided two pairs of tubes. One tube of each pair is fixed at oneend to the piston and moves with it. The other tube of each pair isfixed at one end to a stationary part of the engine, and the free endsof the two tubes of each pair are in telescoping relation to each other,with the movable tube extending outside the stationary tube. A packingor sleeve is provided between the two tubes of each pair. Water or othercoolant flows under pressure into one of these stationary tubes, intothe movable tube in telescoping relation therewith, through a cavity inthe piston, and back out through the other pair of tubes. The movabletubes extend moreover through packings into a chamber which is closedoff from the engine crankcase, and the stationary tubes have their fixedends within this chamber. Separate conduits connect the stationary tubeswith coolant supply and return facilities outside the engine. Anadditional conduit permits withdrawal of coolant accumulating in thischamber, which is moreover connected, at the upper part thereof with theatmosphere outside the engine. The free end of one or both of thestationary tubes is shaped to act as an ejector with the aid of thecoolant flowing through it. The suction space of the ejector thusprovided is connected by a conduit or conduits with the annularsleeve-like space between the telescoped portions of the tubes in whichthis ejector is located. The ejector action occurring upon the flow ofcoolant thus acts to aspirate air and/or coolant which may find its wayinto this annular space. A storage space may be provided incommunication with these conduits, within which coolant may accumulatebetween the intervals of intensive ejector action, which varies due topiston motion.

Field .0) the invention The present invention relates to liquid coolingof the pistons in piston-type internal combustion engines. andparticularly to means for preventing loss or contamina tion (as bylubricating oil) of coolant employed for that purpose.

Description of the prior art It has already been proposed to cool anengine piston by means of two tubes fixed at one end to the piston andmoving therewith, the tubes passing with their free ends throughpackings into a stationary chamber, and to pro- Vide a stationary tubefixed at one end in that chamber, with its free end extending intelescoping relation into one of the movable tubes and having moreover anozzle at that free end through which a coolant such as water is forcedunder a pressure of some three to four atmospheres into the coolingspace of the piston. The heated water passing out of the cooling spaceflows through the second movable tube into the chamber, from which it istransferred to a cooler or other heat dissipating device. In

such a construction difficulties may be experienced at the packingsbetween the chamber and the remainder of the engine, where the movabletubes pass into the chamber. Thus water can leak out of the chamberalong the tubes at these packings, into the space beneath the piston.This entails water losses which can be very disadvantageous in marineengines, where this will be fresh water. Moreover, there exists also thedanger of contamination of the cooling water by residual products ofcombustion which may contain oil or other lubricants.

It has moreover already been proposed to dispose a second stationarytube, with its free end in telescoping relation with the movable tubewhich serves for withdrawal of the cooling water. This second stationarytube connects to a suitable exit line and carries off a large part ofthe flow of water so that only a small proportion thereof falls into thechamber. In this way, it is possible to reduce significantly thedifiiculties above referred to. In particular, the packings between thechamber and the underside of the piston are subjected to much lesssevere operation.

Summary of the invention The invention provides a further improvement inthis direction. By means thereof, the emergence of cooling liquid fromthe tubes into the chamber is still further reduced, with the particularadvantage that there is excluded the possibility of contamination of thecooling water by oil and incompletely burned fuel seeping out of thecombustion chamber above the piston.

In accordance with the invention, there is provided at the free end ofone or both of the stationary tubes :1 nozzle shaped to act as anejector with the aid of the coolant flowing through it. The suctionspace of the ejector thus provided is connected by a conduit or conduitswith the annular sleeve-like space between the telescoped portions ofthe tubes in which this ejector is located. The ejector action occurringupon the flow of coolant thus acts to aspirate air and/ or coolant whichmay find its way into this annular space. A storage space may beprovided in communication with these conduits, within which coolant mayaccumulate between the intervals of intensive ejector action, whichvaries due to piston motion. A ring or packing may also be providedbelow the portion of the sleeve- -like space to which the conduitsconnect. and this packing may be given a desired clearance from theother of the two telescoping tubes, so as to control the aspiration ofair at the ejector.

Brief description. 0 the drawing The invention will now be furtherdescribed with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary transverse sectional view of a diesel or otherinternal combustion engine into which the cooling apparatus of theinvention has been built;

FIG. 2 is a sectional view taken along the lines 2--2 in FIG. 1, shownat an enlarged scale; and

FIGS. 3 and 4 are fragmentary axial sections, shown at a still largerscale, of the pairs of tubes 9, 20 and 10, 21 of FIG. 2 respectively.

Description of preferred embodiment The engine fragmentarily shown inFIG. 1 includes a cylinder 1, a piston 2 having a hollow head 3, apiston rod 4 with a crosshead 5, and a crank housing or crankcase 6.Between the cylinder 1 and the crankcase 6 is disposed an air chamber 7separated by means of partitions 8 from the crankcase.

Cooling of the piston is effected with the aid of two pairs of tubes 9,20 and 10, 21. The tubes 9 and 10 are affixed at one end, the upper endthereof in the embodiment illustrated, to the piston and they movetherewith.

They extend parallel to the direction of travel of the piston. The tubes20 and 21 are affixed at one end, the lower end thereof in theembodiment illustrated, to the inside of a stationary chamber 12. Thetubes 20 and 21 have an outside diameter smaller than the insidediameter of tubes 9 and 10, and their free upper ends extend intelescoping relation with and inside of the free, lower ends of thetubes 9 and 10 respectively. The tubes 9 and 10 may have the samediameter. Packings 11 are provided between the movable tubes 9 and 10and the chamber 12, which is closed ofi from the crankcase 6.

Conduits 13 and 14 connect to the interior of the stationary tubes 20and 21 respectively at the lower ends thereof, and serve respectivelyfor the supply of coolant to the piston and for the withdrawal ofcoolant therefrom. An additional conduit 15 leads out of the chamber 12at the lower end thereof for removal of coolant accumulating therein,and a conduit 22 provides communication between the upper portion ofchamber 12 and the atmosphere outside the engine (FIG. 2). The conduits14 and 15 may be provided with sight glasses 16 and 17 (FIG. 1).

Referring to FIG. 3, the upper end of the stationary coolant inlet tube20 has affixed thereto an annular ejectorshaped nozzle member throughwhich coolant may be sprayed under pressure into the cavity 3 of thepiston via the movable tube 9. The member 30 is provided at its lowerend with a spray nozzle opening 31 which leads into an ejector bore orthroat 32. An annular enlargement 33 is provided at the lower end of theejector throat 32, and this enlargement connects via conduits 34,extending obliquely outward and downward (i.e. backwards, with respectto the flow of coolant through member 30) to an annular space 35. Thespace 35 may be formed at the cylindrical interface between the member30 and a sealing or packing sleeve 36 disposed between the member 30 andthe inside wall of the movable tube 9, and affixed to the former. Thesleeve 36 has a number of circumferential grooves 37 formed in its outersurface, and the lowest groove or grooves 37 are connected by apertures38 with the space 35. The tube 20 has affixed to the exterior thereof,below the nozzle member 30, a ring 28 having a radial clearance X (FIG.3) from the inside wall of the tube 9. This clearance is smaller thanthe clearance between tubes 20 and 9 and is so dimensioned as ot permita desired air flow therethrough and may amount for exampie to some 0.2%of the internal diameter D of the tube 9.

During operation of the engine, a suitable coolant such as water flowsunder a pressure of from 3 to 4 atmospheres through the nozzle 31 andthe ejector opening 32. The flow of water creates a negative pressure inthe hollow space 33. By means of this reduced pressure the medium,liquid or gaseous, in the annular space 29 between the moving tube 9 andthe stationary tube 20 is aspirated through the openings 38, the hollowspace 35 and the bores 34 into the central ejector bore 32. In this wayair is aspirated from the chamber 12 (which is connected to the exterioratmosphere through the conduit 22), and this air is added to the coolingwater. There is thus provided to the cooling space 3 of the piston amixture of air and water, in a manner which in and of itself is alreadyknown. Simultaneously, water which may have penetrated into the annularspace between the tubes 20 and 9, for example by leakage past the sleeve36, is aspirated and returned to the stream of cooling water flowing tothe piston. By means of the ejector operation thus provided for thecoolant supply tube 20, it is possible to effect substantially completesuppression of the passage of water into the chamber 12 via the annularspace between the moving tube 9 and the stationary injection tube 20.

FIG. 4 shows a corresponding construction for the free end of thestationary return tube 21. The tube 21 is provided at its upper end withan annular member 38'. The upper end of this member has a nozzle-likeopening 40, followed at the lower end thereof by an ejector-shapedthroat or bore 41. At the junction of the two is provided a hollowannular space 42 of enlarged diameter, similar to the space 33 in themember 30 already described.

Upon the downward streaming of the cooling water which returns from thepiston, a negative or reduced pressure is developed in the space 42. Thehollow space 42 is connected by bores 43 with a hollow space 44 similarto the space 35' of the tube 20. A packing sleeve 45, simi lar to thesleeve 36 and having circumferential grooves 46 in its outer surface,fits between the return tube nozzle member 38' and the inside wall ofthe movable return tube 10. The lowest of the grooves 46 connects viaopenings 44' with the annular space 44, which functions as a storagespace for liquid in a manner similar to that of the annnlar space 35 ofFIG. 3.

The stationary return tube 21 carries, below the return nozzle member38', a ring 47 generally similar to the ring 28 of FIG. 3. The ring 47has however a smaller clearance from the tube 10 than the clearance X ofFIG. 3, since there is less necessity for an aspiration of air in thecase of tube 21 than in the case of tube 20.

As with the construction of FIG. 3 previously described, in the case ofthe return tube of FIG. 4 also, water which has penetrated into theannular space between tubes 10 and 21 is aspirated by the suction effectof the ejector provided in the member 38.

By means of the present invention, flow of the cooling medium such aswater into the chamber 12 is substan tially prevented. This avoidscontamination of the coolant from oily residual materials penetratingfrom outside the movable tubes, even with a substantial simplificationin the packing 11 between the space beneath the piston and the inside ofthe chamber 12. With the construction of the invention, this packingneed not have a filtering or cleansing action, and suflices if it simplypreserves the existing differences in air pressure.

Storage spaces for coolant are formed by the grooves 37, 46 and thehollow spaces 35 and 44. Since tubes 9 and 10 move up and down with thepiston, the streaming of coolant in the tubes 20 and 21 occurs in a moreor less pulsating fashion so that the suction effect of theejectorshaped end portions thereof is similarly pulsating. The coolantnot aspirated during a phase of reduced suction effect can be collectedin these storage spaces, especially the spaces 35 and 44, and thenremoved or aspirated during the next phase of increased suction effect.

There is achieved an improved suction effect by virtue of the fact thatthe bores 34 and 43 extend obliquely outward and backward (with respectto the direction of coolant flow through their associated ejectors). Theair or water aspirated into the coolant stream is added to the lattersubstantially in the latters direction of fiow and consequently does notimpose an undesirable turbulence on the stream of coolant fluid.

Consistently with the invention, the provision of an ejector ashereinabove described may be applied to the inlet or injection tubethrough which coolant flows into the piston, without being applied alsoto the outlet or return tube. Indeed, it may successfully be applied tothe inlet tube even in constructions in which the tube 21 is absent, themovable return tube (such as that shown at 10 in the drawings) simplydischarging the returning coolant into the chamber. Even with such aconstruction there is achieved a great reduction of the amount of waterflowing into the chamber since the leakage into the chamber which wouldotherwise occur at the junction between the stationary and movable inlettubes is minimized.

While the invention has been described hereinabove in terms of apresently preferred embodiment, the invention itself is not limitedthereto. For example, it is of course not necessary for the stationarytubes to terminate within the chamber 12. Rather, their lower ends maypass out, at liquid-tight seals, through the bottom of that chamber.More generally, the invention comprehends all variations on anddepartures from the embodiment so described which properly fall withinthe spirit and scope of the appended claims.

I claim:

1. Apparatus for liquid cooling of a piston in an internal combustionengine, said apparatus comprising a chamber closed off from the enginecrankcase, a plurality of movable tubes affixed at one end to the pistonand extending at their other ends into the chamber, and at least onestationary tube having a free end extending for all positions of thepiston in telescoping relation with the other end of one of said movabletubes, wherein the improvement comprises an ejector-shaped membersupported adjacent the free end of said one stationary tube, said memberhaving a space within said one stationary tube in which flow of liquidthrough said member creates a reduced pressure, and conduit meansconnecting said space with the annular space between the portions ofsaid stationary tube and said one movable tube which are in telescopingrelation.

2. Apparatus according to claim 1 wherein said ejectorshaped membercreates a reduced pressure in said firstmentioned space upon flow ofliquid through said stationary tube toward said one movable tube.

3. Apparatus according to claim 2 including a ring disposed on theexterior of said stationary tube in the part thereof having telescopingrelation with said one movable tube, said ring having a smallerclearance from the inner Wall of said one movable tube than does saidstationary tube.

4. Apparatus according to claim 1 wherein said ejectorshaped membercreates a reduced pressure in said firstmentioned space upon flow ofliquid through said stationary tube from said one movable tube.

5. An apparatus according to claim 1 wherein said member is an annularmember having an axis, wherein said first-mentioned space constitutes anannular enlargement of the opening through said annnlar member, andwherein said conduit means comprise a plurality of bores disposed aboutsaid axis and extending outwardly from said first-mentioned space.

6. Apparatus according to claim 5 wherein said bores extend obliquely tosaid axis.

7. Apparatus according to claim 1 wherein said member has formed thereinan annular space communicating with said conduit means intermediate theends thereof.

8. Apparatus according ot claim 2 including means to permit withdrawalof liquid accumulating in said chamber, and means to permit themaintenance of atmospheric pressure within said chamber.

References Cited UNITED STATES PATENTS 3,230,940 1/1966 Hofmann 123-41363,230,941 1/1966 Hofmann 123-4136 3,230,942 1/1966 Hofmann 123-41363,230,943 1/1966 H-ofmann 123-4136 WENDELL E. BURNS, Primary Examiner.

